It is known in the art to fold multiple section planters and drills forwardly from wide spread field positions to narrowed transport positions. However, in many multiple sections machines gauge wheels on the wing sections project forwardly from the front side of the sections and thus tend to interfere with one another when the sections are folded together. To avoid these interference problems, pivot points for the wing sections are typically spaced far enough apart to keep the gauge wheels from interfering with one another when the machine is in its folded condition. However, this necessarily increases the overall width of the folded machine.
The present invention solves this problem by making the gauge wheel assemblies shiftable from their positions on the front side of the wing sections into outboard positions at the ends of the sections during folding of the wings into their folded positions. This clears out the space otherwise occupied by the gauge wheels on the front side of the wing sections and allows the wing sections to come closer together in the folded position, resulting in a reduced overall width of the machine.
The ground engaging wheel of each gauge wheel assembly comprises a self-aligning castor wheel that reacts to ground forces during the folding and unfolding sequence so as to reorient itself with the path of travel of the machine. A positive, hydraulic-operated latch locks the castor wheels in straight-ahead positions during field operations, and a spring-loaded detent yieldably maintains the castor wheels in straight-ahead positions during over-the-road travel. The gauge wheel assemblies are shifted between their inboard and outboard positions by hydraulic cylinders that are coupled in master-slave relationship with fold cylinders for the wing sections, so that folding of the wing sections and repositioning of the gauge wheels occur simultaneously. Instead of a long central tongue, the machine utilizes a pair of pull bars that are coupled at their rear ends to the wing sections and converge forwardly to a common hitch member that is connected to the towing tractor. Ball swivels at the rear ends of the pull bars allow for independent flexing of the wing sections as uneven terrain is encountered.